A systematic review of instruments to measure health literacy of patients in emergency departments

OBJECTIVES: Knowledge of patient's health literacy (HL) in the emergency department (ED) can facilitate care delivery and reduce poor health outcomes. This systematic review investigates HL measurement instruments used in the ED and their psychometric properties, accuracy in detecting limited HL, and feasibility. METHODS: We searched in five biomedical databases for studies published between 1990 and January 2021, evaluating HL measurement instruments tested in the ED on internal consistency, criterion validity, diagnostic accuracy, or feasibility. Reviewers screened studies for relevance and assessed methodologic quality with published criteria. Data were synthesized around study and instrument characteristics and outcomes of interest. RESULTS: Of the 2,376 references screened, seven met our inclusion criteria. Studied instruments varied in objective (n = 5) and subjective (n = 6) measurement of HL skills, and in HL constructs measured. The Brief Health Literacy Screen (BHLS) and the Subjective Numeracy Scale demonstrate acceptable and good internal consistency across studies. None of the instruments perform consistently well on criterion validity. The Rapid Estimate of Adult Literacy in Medicine–Revised and the Newest Vital Sign, both objective tests with short administration times, demonstrate good accuracy in one study with high risk of bias. The BHLS, a short subjective measure, shows moderate accuracy across studies including one with low risk of bias. CONCLUSIONS: Several short instruments seem valid in measuring HL and accurate in detecting limited HL among ED patients, each with its practical advantages and disadvantages and specific measurement of HL. Additional research is necessary to develop a robust evidence base supporting these instruments.